The present invention relates to a portable surface preparation abrading unit of that type which is employed to safely remove surface coatings of a toxic or hazardous nature without contaminating the ambient work area environment, such as metallic bottom paints used on boat hulls and the like, and to collect the removed surface coating dust and debris for environmentally safe disposal.
Other than for the slow and costly process of manual removal of toxic or environmentally unsafe surface coatings, the hazardous nature of which may be due to the coating itself or a fouling film upon the surface, or a combination thereof, the two basic mechanically assisted manually portable means for removing such coatings are by either some sort of so-called blasting apparatus which incorporates the use of a pressurized slurry or air stream to fluidize and direct abrading particulate matter such as sand against the coating or film on the surface to be cleaned or prepared, or a mechanically driven sanding unit with either orbital or rotary sanding elements in combination with a vacuum source in order to draw off the surface removed dust and debris so that it does not contaminate the work area environment and also to collect the same for safe handling and environmentally safe disposal.
Exemplary of the portable blasting type of surface preparation apparatus would be those as respectively taught by Atsuchi in U.S. Pat. No. 4,149,345 dated Apr. 17, 1979, for a recirculating sand blaster specifically adapted for use in cleaning ship hulls, and by Brown in U.S. Pat. No. 4,375,740 dated Mar. 8, 1983, for a hand-held portable blasting unit also embodying a recycling abrasive system.
With regard to the exemplary sanding unit type of surface preparation unit with vacuum removal of dust and debris, typical teachings would be those as respectively set forth in U.S. Pat. No. 4,422,239 to Maier et al dated Dec. 27, 1983, and U.S. Pat. No. 4,782,632 to Matechuk dated Nov. 8, 1988, the latter of which also embodies the use of a flexible drive shaft component for the orbital sander.
Applicants herein by their teaching disclose in addition to a vacuum system removal means, the use of a flexible drive for operating the sander, another teaching of which shows a similar such use being that of Brook in U.S. Pat. No. 4,276,673 dated Jul. 7, 1981, for a flexible drive shaft upon a floor wax stripping apparatus.
The applicants herein by their invention, however, provide a convenient new and novel portable surface preparation abrading unit having the advantage of being able to mechanically remove a surface coating with ease and efficiency substantially without dust and debris contamination therefrom of the ambient work area environment, and with highly efficient means to withdraw and collect the removed dust and debris for safe handling and environmentally safe disposal thereafter.